Driver Assembly (08970-60089) - HP 8970B Service Manual

Board Differences

Driver Assembly (08970-60089)

Driver Assembly (08970-60089)
The 08970-60089 assembly has been created from the 08970-60034 assembly with the
following changes:
1. R25, 26, 27, R39, R40 and R41 change from 214.2
3460)
2. Q2 is deleted and a wire is place between U33 pin 14 and the base of Q3.
Figure 4-2: Schematic differences in 08970-60089
12
+
U33D
3
13
-
R24
3060
C28
1 uF
3
5V (F1)
REGULATOR
1. Differences are highlighted with a shaded background.
4-4
14
Q3
G
R25 R26 R27
121 121 121
3 3 3
(SEE NOTE 9)
R57
100
C58
6.8 uF
+
-5 VOLT
3
HP 8970B Option 020 Service Manual Supplement
(0699-1911) to 121
1
VR2
13V
C55
L
1000 pF
D
1ST LO
DRIVE
19
S
R39 R40 R41
121
121
121
3 3
3
(0699-
1ST LO
GND
8